Rotary engine.



PATENTED PEB. 13, 1906.

R. C. MOLEAN.

ROTARY ENGINE.

APPLICATION FILED SEPT. 29, 1905.

NVENTOH A TTOHNE UNITED STATES PATENT OFFICE Specification of LettersPatent.

Patented Feb. 13, 1906.

Application led September 29, 1905. Serial No. 280,668.

To all whom t may concern:

Beit known that I, ROBERT CoRMAoK Mc- LEAN, a subject of the Kin ofGreat Britain, and a resident of Olevelan in the county of Cuyahoga andState of Ohio, have invented a new and Improved Rotary Engine, of whichthe following is a full, clear, and exact description.

This invention relates to rotary engines.

The object of the invention is to provide an engine of this class whichis simple in construction and which will operate eHiciently with littlewaste. c

A further object is to provide such an engine with an improvedarrangement for the exhaust-ports.

The invention consists in the construction and combination of parts tobe more fully described hereinafter and definitely set forth in theclaims.

Reference is to be had to the accompanying drawings, formino a part ofthis specification, in which simi ar characters of reference indicatecorresponding parts in both views.

Figure 1 is a longitudinal section through an engine constructedaccording to my invention, a portion of the shaft thereof being shown inelevation. This section is taken substantially upon the line 1 1 of Fig.2. Fig. 2 is a vertical cross-section through the engine, taken at rightangles to the shaft.

Referring more particularly to the parts, 1 represents the casing of theengine, which is preferably formed of a cylindrical body 2, having 'anintegral base 3 adapted to rest upon a suitable support. The casing alsoincludes side plates 4 and 5, which are bolted to the opposite sides ofthe body 2, as indicated. In thc side platos 4 and 5 a shaft 6 ismounted to rotate. In order to make this shaft substantially steam-tightin the side plate 4, a stuffing-box 7 of suitable construction, such asthat shown, is provided. The shaft 6 is provided with acentrally-disposed bore 8, which extends in from the extremity9 thereof.At this extremity 9 the shaft is provided with openings 10, which passthrough the wall thereof, so as to open communication to the bore 8, asindicated. Adjacent tov these openings 10 the shaft is provided with anintegral collar 11. Under this collar suitable packing 12 is arranged,and a bonnet 13 is disposed over the end of the shaft, the same beingscrewed upon a threaded 'nipple 14, which projects from the side plate5, as shown.

lVithin the interior of the bonnet 13 beyond the collar 11 an inletsteam-chamber 15 is formed, into which live steam is admitted through asuitable pipe connection 16. The steam in this inlet-chamber 16 flows inthrough the openings 10 into the bore 8, passing from this point to theinterior of the en- Upon the shaft 6 within the interior of the casinthere is rigidly mounted a drum i. barre 17. This drum, as indicatedmost clearly in Fi 2, is of cylindrical form and provided wit a centralbore or chamber 18,

which constitutes a steam-chest. Steam is admitted to this steam-chestthrough open.

ings 19, which are formed in the s aftand which communicate with thebore 8 there=:.-f, carrying the steam. The outer face of the drum 17 isprovided with a plurality of radially-disposed slots or guideways 20, inwhich there are slidably mounted a corresponding number of pistons orvalves 21. These valves consist of fiat lates having side extensions orlegs 22, as s own in Fi 1, and these legs extend down at the end aces ofthe drum, bein disposed in slots 23 at these points, whic constituteextensions of the 'slots 20, as will be readily understood. The inneredges of the bodies 24 of the pistons are preferabl y beveled, asindicated at 25. Between these edges 25 and the bottoms of the slots 20steam-spaces 26 are formed, and steam is admitted into these steam-saces by means of ports 27, which pass radiallfy from the steamchest 18.As indicated, there are preferably six ofthese istons 21 operating inthe same number of sfots 20.

The inner face of the body 2 of the casing is substantially cylindricalin form, but provided with four abutments 28, which roject inwardly, sothat their inner faces at t eir innermost points lie substantiallyagainst the cylindrical face of the drum 17. spect to the direction ofrotation the forward faces 29 of these abu'tments are slightly inclinedor curved, while the rear faces 30 are more abrupt and preferablystraight, as shown. pockets or expansion-chambers 31 are formed. Thewalls of these pockets between the abutments arc substantiallycylindrical, being disposed upon the axis of the shaft 6 as an axis ofcurvature. Adjacent to the faces 11o vVith re- Ioo Between theseablatments 28 four 105 30 the width of the expansion-chambers measuredradially is increased by reason of the fact that the bore at this partis depressed away from the drum 17, as indicated at 32. The wall 33beyond these points is elevated. The purpose of this arrangement will bedescribed more fully hereinafter.

In the abutments 28 and near the angle formed between the inclined faces29 and the faces 33 I provide main exhaust-ports 34, the same beingprovided with lateral branches 35, as indicated in Fig. 1, which openinto the pockets or expansion-chambers 31, as indi! valves 21 outwardly,maintaining their rounded noses 38 against the wall of the casing. Inthe position in which the drum 17.is shown cut-off has just taken place.This cuto occurs when the ends of the pistons 21 ride up from thesurfaces 32 upon the elevated surfaces 33. When the pistons have theirnoses resting against the depressed faces 32, the inner edges 25 of thepistons are disposed beyond the periphery of the drum 1-7, so that thesteam behind the valves is allowed to escape. This steam filling theexpansion-chambers behind the pistons of course operates to rotate thedrum and aclvance the pistons in the direction of the elevated faces 33and toward the inclined faces 29; When the rotation has continuedsufficiently, the exhaust-ports 34 are uncovered at their branches 35,so that the steam escapes, creating an exhaust from theexpansion-chamber. The steam which remains in the chambers in front ofthe pistons when they have passed' beyond the exhaust-ports 34 isexpelled through the auxiliary ports 36. In this way no back pressure isdeveloped at the abutments 28 which might tend to prevent the rotationof the engine. When the pistons pass the most elevated points of theabutments 28, they slide down or outwardly on the inclined faces 30toward the faces 32,

admitting steam again to the expansionchambers. This admission of thesteam continues, of course, until cut-off occurs by the inward movementof the pistons, when they pass up to the elevated faces 33.

While I have described the engine as a steam-engine, its use is by nomeans confined to this gas, and it may be operated by any other gas,such as compressed air. Indeed, it could be operated by water.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. In a rotary engine, in combination, a casingpresenting a substantially cylindrical body, a drum rotatably mountedwithin said body, a plurality of pistons projecting radially from saiddrum and normally engaging the inner face of said body, said body havingabutments projecting inwardly and substantially abutting the cylindricalface of said drum, said casing further having exhaustports near saidabutments, said abutments presenting inclined forward faces along whichsaid pistons pass and aumliary ports in said inclined faces.

2. In a rotary engine, in combination, a casing presenting asubstantially cylindrical body, a drum rotatably mounted wlthn saidbody, said casing havin a plurality of abutments projecting towar saiddrum and substantially abutting the outer surface thereof whereby aplurality of expansion-chambers are formed between said abutments, saidabutments having inclined faces disposed forwardly with respect to thedirection of rotation of said drum, means for admitting steam to theinterior of said drum, said drum having steam-spaces, a plurality ofpistons guided in said drum and backed by said steam-spaces whereby thesteam operates to maintain said pistons in engagement with the saidcasing, said casing having exhaustports adjacent to said abutmentsadapted to be uncovered by the advance movement of said pistons, andfurther having auxiliary exhaust-ports opening on said inclined faces,loo

said auxiliary exhaust-ports affording escape for steam held before saidpistons after passin said first exhaust-ports.

In testimony whereof I have signed my name to this specification in thepresence of m5 two subscribin witnesses.

ROBE T CORMACK MCLEAN. Witnesses:

THOMAS C. RUSSELL, JAMES A. FREW.

